Crank shaft



July 7,1931. C. C. FARMR 1,813,153

CRANK SHAFT Filed Dec. 27,. 1929 l5 I4 |NVENTOR CLYDE C. FARMER ATTORNEY Patented July k7, 1931 UNITED STATES F PENNSYLVANIA cLYDE c. FARMER, ork PITTSBURGH, :en-NNsYIQvri-iaTA,fAs'sTGNORl To THE wns'TING- HOUSE AIR :BRAKE COMPANY, OF WILMERDTNG; PENNSYLVANIA, A CORPORATION CRAN K SHAFT Application led December 277, 1929. Serial 110.416,871.

This invention relates to crank shafts, and more particularly to a crank shaft having gears associated therewith.

In some cases, gears are associated with c crankl shafts, as in the case of certain typesv of Huid compressors, in which the fluid controlling valve mechanism. is operated by gears on the crank shaft.l

Such gears must be accurately cut and positioned, and this is rendered difficult, if the v gears are formed integral with the crank shaft. On the other hand, it is difficult to apply gears to ay crank shaft, so that the gears will be accurately positioned, and' it is ditlicult to so construct the gears that they may be readily applied to the crank shaft and firmly secured in position.

The principal object of my invention is to provide an improved geared crank shaft in f which the above diiiiculties are overcome.

In the accompanying drawings; Fig.v 1 is an elevational view, in one plane, of a geared crankV shaft embodying my invention; Fig. 2 an elevational view of the crank shaft in ay Vg5 plane at right angles to that of Fig. 1; Fig.`

3 a section on the line 3-3 of Fig. l; Fi 4 a section on the line 4-4 of Fig. 1 and ig.

5 a detail view of the crank arm.

The crankshaft 1, as shown in the drawings, is ada ted for a three cylinder fiuid compressor not shown) and has three connecting rod bearing pins 2, 3, and 4. The

bearing pin 2 is carried by crank arms`5 and 6, the bearing pin 3 by arms 6 and 7, and the bearing pin 4 by arms 7 and 8..

The crank arms 6 and 7 are adapted to carry gears 9 and 10 respectively and each crank arm is provided adjacent to the pin 3 with an integral iange 11. VEach arm is formed 4o adjacent to the flange with machined fiatV parallel sides 12 and arcuate ends 13 and 14, concentric with the main shaft of the crank shaft.

Each gear is provided withvan opening ,y adapted to snugly it over the crank arm section above described and the crank arm seoi -tion is out away as shown at 15 and also at 16 and 17 to facilitate the assembly of the gear on the shaft. Each gear is also chamfered as shown at 18.

In assembling, the gear 9 is threaded over the crank arm 5, which arm is of a size and contour to permit same to pass through the opening in the gear. The gear is then threaded over the crank arm 6, the chamfer 18 facilitating the mo'vemenuwith respect to the inclined portiony 20 of the 'crank arm. The gear is cocked with the lower portion held toward the left, as it is brought into engagement with the flange 11, so that the lower arcuate end of the openingvin the gear will clear the lower arcuate portion14. The gear is then swungV toward the right at its lower end, so that the gear engages the flange V11, Y

as shown in Fig. 1. lA dowel pin 21 extends into bores formed in the gear and in the crank arm, for the purpose of accurately alining the gear and preventing the gear from being positioned on the shaft in an incorrect manner. y.

Rivets 22 are then inserted in alined bores in the gear and the crank arm and are riveted down, so as' tovirmly secure the gear in place. The gear '10 is applied in position in thesame manner as the gear 9.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than yby the terms of thel appended claims.

Having'now described my invention, Vwhat I claim as new and desire to secure by Letters Patent, is:

1. A crank shaft having a crank arm, a section of which has a contour including parallel sides, a gear mounted on said section having an Opening, the contour of which corresponds with the contour of said section, a flange formed f at one side of said section against which the gear bears, and means for securing said gear in position on said section.

2. A crank shaft having a crank arm, a section of which has a contour including parallel 5 sides and arcuate ends, a gear mounted on said section having an opening, the contour of which corresponds With the contour of said section, one of the arcuate ends being cut away laterally and longitudinally to facilitate 10 the assembly of the gear on the section, and means for securing the gear in position on the section.

In testimony whereof I have hereunto set my hand this 23rd da of December, 1.929. 15 CL E C. FARMER. 

